1. Field of the Invention
The invention relates generally to the field of inspection systems. More particularly, the invention relates to a remote sensing device to detect materials of varying atomic numbers.
2. Discussion of the Related Art
The identification of weapons-grade materials (such as uranium, plutonium, or radiation dispersion devices known as “dirty bombs”) concealed within cargo containers is of growing importance worldwide.
Typically, instruments such as Geiger counters and gamma ray detectors are employed at ports-of-entry to scan such containers. Nevertheless, these technologies have limited applications. For example, highly-enriched uranium (235U) does not emit a significant flux of gamma rays, and can be easily shielded by a thin layer of lead.
Meanwhile, it is known that by measuring photon attenuation, one can identify materials with large atomic numbers. In order to accurately interrogate a cargo container, a high-energy beam of photons with high penetrating power may be used. Further, a detection system that can identify materials of varying atomic number is needed.
Until now, the requirements of a method and/or apparatus for probing closed containers for weapons-grade fissile materials of varying atomic number with a high-energy photon beam, and resolving the energy and attenuation of the outgoing flux of photons from the container has not been met.